Infrasound animals
January 3, 2005 6:48 PM   Subscribe

"Infrasonic Symphony" Intrigued by reports of tsunami-avoidance behavior in Sri Lankan wildlife? Science News offers a timely antidote to simplistic mumbo-jumbo about the "mythical power" of animal earthquake detection with a detailed look at the latest research into low-frequency sound. The Elephant Listening Project is particularly interested in elephant rumblings that produce Rayleigh waves. "Mammals, birds, insects, and spiders can detect Rayleigh waves," notes The Explainer. "Most can feel the movement in their bodies, although some, like snakes and salamanders, put their ears to the ground in order to perceive it."
posted by mediareport (15 comments total)

 
Human studies are also underway, although the one I cite seems rather sloppy to me.
posted by mediareport at 7:08 PM on January 3, 2005


I have a hard time accepting the anecdotal stories about wildlife escaping the tsunamis. First of all, I'm sure the vast majority of rescuers are only concerned about the human toll of the tsunamis and are ignoring any dead rats they find in the water. Second, rescuers are working in places that were for the most part filled with large human populations and consequently low wildlife populations - in the places with high human casualties, there probably weren't many wild animals to begin with. Third, who's going to remote inaccessible places to look for dead animals, and who knows what the animal populations were like in those places before the tsunamis struck? Finally, if mammals like rabbits and elephants have sixth senses for natural disasters, why don't we? We're mammals too and were wild animals in the not too distant past. And no dead birds? Of course not - they could just fly away.
posted by driveler at 7:24 PM on January 3, 2005


Those are great questions, driveler. I definitely share your desire for more information before accepting the reports of animal avoidance, and hope that a semi-scientific survey, at least, occurs to attempt to verify the initial reports of few or no deaths among, say, small to large mammals. I do believe the elephant and leopard populations were being monitored regularly, so perhaps changes will be detectable. From what I've been able to find, most of Yala Park *was* heavily hit by the tsunami, so I do think it would be interesting if no dead wild mammals turn up at all.

Regardless, the evidence for animal detection of Rayleigh waves seems very well-established, even if scientists aren't yet sure exactly how elephants, e.g., might be receiving them. This stuff is fairly new to researchers, remember.

Finally, if mammals like rabbits and elephants have sixth senses for natural disasters, why don't we?

That's what makes this so intriguing, no? Is it possible that we humans have surrounded ourselves with so much (generally high-frequency?) stimulation that lower-frequency warnings - warnings our species once might have noticed - just get lost in all the noise and busy-ness?
posted by mediareport at 7:41 PM on January 3, 2005


...and, of course, not all animals can detect Rayleigh waves. They just watch the elephants. :)
posted by mediareport at 7:50 PM on January 3, 2005


That's what they say in the Explainer link. It's low priority and hence ignored.
posted by dhruva at 7:51 PM on January 3, 2005


There may be no need for a sixth sense to explain this. Animals have warning systems that are visual, e.g., flashing colors, feathers, etc., as well as sounds that are simply too subtle for us clumsy, impatient, unobservant humans. Animals live in social networks that we can only understand by patient observation in natural habitats. The flight of one species may be triggered by an entirely different species. Where I live, the robins are the sentries. They have one kind of persistent chirp for a cat in the underbrush, different, more frantic chirps (combined with dive-bombing) for crows and ravens at nesting time or horned owls at dusk. They have still another high, almost ultrasonic descending whistle at about 15 second intervals, for smaller hawks that would prey on the robins themselves and smaller animals. This last sound is high and quiet enough to be very difficult to pinpoint. The robins, meanwhile, are completely motionless in the trees, and there are no other sounds. The quail, squirrels, and other birds and small mammals have taken cover. The robins take on this sentry position, putting themselves at risk for tradeoffs I have yet to understand. But after many years observing this, I can walk out in my yard and know, just by listening to the robins, whether there is an owl, cat, crow, or hawk. So during the tsunami, it may have taken only one species to trigger the escape of others. This is not to mention the effect of screaming and running humans on wild animals that, for the most part, avoid humans and run much faster than we do. Lastly, humans are the only animals I know that go down to the water to watch big waves roll in. I know I do.
posted by weapons-grade pandemonium at 8:41 PM on January 3, 2005


I grew up in Los Angeles and have heard of a few times where one student in a classroom might jump under their desk right before an earthquake actually hits. I also remember one morning when my family's pet birds suddenly got in a huge panic and my youngest sister (then about 18 months I think) started fussing and crying even though she usually woke quietly... A few minutes later, there was an earthquake.

Of course these are just stories. They've always made me wonder, though.
posted by halonine at 8:51 PM on January 3, 2005


Key concept: Pacinian corpuscles.
posted by raygirvan at 8:56 PM on January 3, 2005


Re pandemonium's post, I don't think anyone else reported that sort of thing for any animal, special warning calls for various animals? I've only heard it about Meerkats, and it's considered highly unusual. Plus, Meerkat calls are (I think) hard-coded and simpler (aerial predators vs. snakes etc.), and you're implying that your Robins actually learn and convey this behavior. You should call a zoologist or something if you really think it's true ;)
posted by abcde at 10:11 PM on January 3, 2005


*has reported
posted by abcde at 10:12 PM on January 3, 2005


Never mind, some very easy research shows that birds also do this :P
posted by abcde at 10:13 PM on January 3, 2005


Making mistakes in comments is the reason I am so very very quite.
posted by TwelveTwo at 10:43 PM on January 3, 2005


Aggh, I did it again!!
posted by TwelveTwo at 10:43 PM on January 3, 2005


The first reports I heard of this were supposed to have come from employees of Sri Lanka's Yala National Park, who were suprised to find that despite the park's proximity to the ocean very few animals died. The source of this information obviously provides an answer for most of driveler's reasonable doubts. I just came across a mention of Yala and the phenomenon in this very recent online discussion with WaPo staff writer Michael Dobbs, who was swimming off the coast of Sri Lanka when the tsunami struck.
posted by Onanist at 12:55 AM on January 4, 2005


The Yala evidence won't be enough in itself to prove or disprove animal sensitivity, which is why I treated it peripherally in the post. Still, here's everything I could dig up (Onanist, Dobbs was simply repeating a widely reported tidbit from the first round of tsunami stories).

From a relatively detailed first-hand report on the damage at Yala posted at Freedom Watch Sri Lanka:


...As such there were no birds to be seen, no small animals grazing on patches of grasslands, no solitary wild elephants towering through the tall mana-grass and not even jungle fowls hurriedly creeping into thickets. The whole area was desolate with absolutely no life.

One widely reprinted AP story included this bit near the top:

An Associated Press photographer who flew over Sri Lanka's Yala National Park in an air force helicopter saw abundant wildlife, including elephants, buffalo, deer, and not a single animal corpse.

In response, Humane Society International posted this [scroll down]:

Despite unconfirmed reports that many wild animals survived the flooding in Sri Lanka's Yala National Park, it may be too early to gauge the tsunami's impact on all populations there. "Only so much can be seen from a helicopter, and the area to be searched from the ground is probably substantial and hard to navigate right now," explained John Hadidian, director of HSUS's Urban Wildlife program.

Again, whatever the real story at Yala, it will be suggestive evidence at best. To me, the new interest in infrasound research is far more fascinating, including Rayleigh waves and the ability of some animals to sense them.
posted by mediareport at 5:41 AM on January 4, 2005


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